Stable Diffusion Advanced Usage Guide
Custom Pipelines
Building from components
`python
from diffusers import (
UNet2DConditionModel,
AutoencoderKL,
DDPMScheduler,
StableDiffusionPipeline
)
from transformers import CLIPTextModel, CLIPTokenizer
import torch
Load components individually
unet = UNet2DConditionModel.from_pretrained(
"stable-diffusion-v1-5/stable-diffusion-v1-5",
subfolder="unet"
)
vae = AutoencoderKL.from_pretrained(
"stable-diffusion-v1-5/stable-diffusion-v1-5",
subfolder="vae"
)
text_encoder = CLIPTextModel.from_pretrained(
"stable-diffusion-v1-5/stable-diffusion-v1-5",
subfolder="text_encoder"
)
tokenizer = CLIPTokenizer.from_pretrained(
"stable-diffusion-v1-5/stable-diffusion-v1-5",
subfolder="tokenizer"
)
scheduler = DDPMScheduler.from_pretrained(
"stable-diffusion-v1-5/stable-diffusion-v1-5",
subfolder="scheduler"
)
Assemble pipeline
pipe = StableDiffusionPipeline(
unet=unet,
vae=vae,
text_encoder=text_encoder,
tokenizer=tokenizer,
scheduler=scheduler,
safety_checker=None,
feature_extractor=None,
requires_safety_checker=False
)
`
Custom denoising loop
`python
from diffusers import DDIMScheduler, AutoencoderKL, UNet2DConditionModel
from transformers import CLIPTextModel, CLIPTokenizer
import torch
def custom_generate(
prompt: str,
num_steps: int = 50,
guidance_scale: float = 7.5,
height: int = 512,
width: int = 512
):
# Load components
tokenizer = CLIPTokenizer.from_pretrained("openai/clip-vit-large-patch14")
text_encoder = CLIPTextModel.from_pretrained("openai/clip-vit-large-patch14")
unet = UNet2DConditionModel.from_pretrained("sd-model", subfolder="unet")
vae = AutoencoderKL.from_pretrained("sd-model", subfolder="vae")
scheduler = DDIMScheduler.from_pretrained("sd-model", subfolder="scheduler")
device = "cuda"
text_encoder.to(device)
unet.to(device)
vae.to(device)
# Encode prompt
text_input = tokenizer(
prompt,
padding="max_length",
max_length=77,
truncation=True,
return_tensors="pt"
)
text_embeddings = text_encoder(text_input.input_ids.to(device))[0]
# Unconditional embeddings for classifier-free guidance
uncond_input = tokenizer(
"",
padding="max_length",
max_length=77,
return_tensors="pt"
)
uncond_embeddings = text_encoder(uncond_input.input_ids.to(device))[0]
# Concatenate for batch processing
text_embeddings = torch.cat([uncond_embeddings, text_embeddings])
# Initialize latents
latents = torch.randn(
(1, 4, height // 8, width // 8),
device=device
)
latents = latents * scheduler.init_noise_sigma
# Denoising loop
scheduler.set_timesteps(num_steps)
for t in scheduler.timesteps:
latent_model_input = torch.cat([latents] * 2)
latent_model_input = scheduler.scale_model_input(latent_model_input, t)
# Predict noise
with torch.no_grad():
noise_pred = unet(
latent_model_input,
t,
encoder_hidden_states=text_embeddings
).sample
# Classifier-free guidance
noise_pred_uncond, noise_pred_cond = noise_pred.chunk(2)
noise_pred = noise_pred_uncond + guidance_scale * (
noise_pred_cond - noise_pred_uncond
)
# Update latents
latents = scheduler.step(noise_pred, t, latents).prev_sample
# Decode latents
latents = latents / vae.config.scaling_factor
with torch.no_grad():
image = vae.decode(latents).sample
# Convert to PIL
image = (image / 2 + 0.5).clamp(0, 1)
image = image.cpu().permute(0, 2, 3, 1).numpy()
image = (image * 255).round().astype("uint8")[0]
return Image.fromarray(image)
`
IP-Adapter
Use image prompts alongside text:
`python
from diffusers import StableDiffusionPipeline
from diffusers.utils import load_image
import torch
pipe = StableDiffusionPipeline.from_pretrained(
"stable-diffusion-v1-5/stable-diffusion-v1-5",
torch_dtype=torch.float16
).to("cuda")
Load IP-Adapter
pipe.load_ip_adapter(
"h94/IP-Adapter",
subfolder="models",
weight_name="ip-adapter_sd15.bin"
)
Set IP-Adapter scale
pipe.set_ip_adapter_scale(0.6)
Load reference image
ip_image = load_image("reference_style.jpg")
Generate with image + text prompt
image = pipe(
prompt="A portrait in a garden",
ip_adapter_image=ip_image,
num_inference_steps=50
).images[0]
`
Multiple IP-Adapter images
`python
Use multiple reference images
pipe.set_ip_adapter_scale([0.5, 0.7])
images = [
load_image("style_reference.jpg"),
load_image("composition_reference.jpg")
]
result = pipe(
prompt="A landscape painting",
ip_adapter_image=images,
num_inference_steps=50
).images[0]
`
SDXL Refiner
Two-stage generation for higher quality:
`python
from diffusers import StableDiffusionXLPipeline, StableDiffusionXLImg2ImgPipeline
import torch
Load base model
base = StableDiffusionXLPipeline.from_pretrained(
"stabilityai/stable-diffusion-xl-base-1.0",
torch_dtype=torch.float16,
variant="fp16"
).to("cuda")
Load refiner
refiner = StableDiffusionXLImg2ImgPipeline.from_pretrained(
"stabilityai/stable-diffusion-xl-refiner-1.0",
torch_dtype=torch.float16,
variant="fp16"
).to("cuda")
Generate with base (partial denoising)
image = base(
prompt="A majestic eagle soaring over mountains",
num_inference_steps=40,
denoising_end=0.8,
output_type="latent"
).images
Refine with refiner
refined = refiner(
prompt="A majestic eagle soaring over mountains",
image=image,
num_inference_steps=40,
denoising_start=0.8
).images[0]
`
T2I-Adapter
Lightweight conditioning without full ControlNet:
`python
from diffusers import StableDiffusionXLAdapterPipeline, T2IAdapter
import torch
Load adapter
adapter = T2IAdapter.from_pretrained(
"TencentARC/t2i-adapter-canny-sdxl-1.0",
torch_dtype=torch.float16
)
pipe = StableDiffusionXLAdapterPipeline.from_pretrained(
"stabilityai/stable-diffusion-xl-base-1.0",
adapter=adapter,
torch_dtype=torch.float16
).to("cuda")
Get canny edges
canny_image = get_canny_image(input_image)
image = pipe(
prompt="A colorful anime character",
image=canny_image,
num_inference_steps=30,
adapter_conditioning_scale=0.8
).images[0]
`
Fine-tuning with DreamBooth
Train on custom subjects:
`python
from diffusers import StableDiffusionPipeline, DDPMScheduler
from diffusers.optimization import get_scheduler
import torch
from torch.utils.data import Dataset, DataLoader
from PIL import Image
import os
class DreamBoothDataset(Dataset):
def __init__(self, instance_images_path, instance_prompt, tokenizer, size=512):
self.instance_images_path = instance_images_path
self.instance_prompt = instance_prompt
self.tokenizer = tokenizer
self.size = size
self.instance_images = [
os.path.join(instance_images_path, f)
for f in os.listdir(instance_images_path)
if f.endswith(('.png', '.jpg', '.jpeg'))
]
def __len__(self):
return len(self.instance_images)
def __getitem__(self, idx):
image = Image.open(self.instance_images[idx]).convert("RGB")
image = image.resize((self.size, self.size))
image = torch.tensor(np.array(image)).permute(2, 0, 1) / 127.5 - 1.0
tokens = self.tokenizer(
self.instance_prompt,
padding="max_length",
max_length=77,
truncation=True,
return_tensors="pt"
)
return {"image": image, "input_ids": tokens.input_ids.squeeze()}
def train_dreambooth(
pretrained_model: str,
instance_data_dir: str,
instance_prompt: str,
output_dir: str,
learning_rate: float = 5e-6,
max_train_steps: int = 800,
train_batch_size: int = 1
):
# Load pipeline
pipe = StableDiffusionPipeline.from_pretrained(pretrained_model)
unet = pipe.unet
vae = pipe.vae
text_encoder = pipe.text_encoder
tokenizer = pipe.tokenizer
noise_scheduler = DDPMScheduler.from_pretrained(pretrained_model, subfolder="scheduler")
# Freeze VAE and text encoder
vae.requires_grad_(False)
text_encoder.requires_grad_(False)
# Create dataset
dataset = DreamBoothDataset(
instance_data_dir, instance_prompt, tokenizer
)
dataloader = DataLoader(dataset, batch_size=train_batch_size, shuffle=True)
# Setup optimizer
optimizer = torch.optim.AdamW(unet.parameters(), lr=learning_rate)
lr_scheduler = get_scheduler(
"constant",
optimizer=optimizer,
num_warmup_steps=0,
num_training_steps=max_train_steps
)
# Training loop
unet.train()
device = "cuda"
unet.to(device)
vae.to(device)
text_encoder.to(device)
global_step = 0
for epoch in range(max_train_steps // len(dataloader) + 1):
for batch in dataloader:
if global_step >= max_train_steps:
break
# Encode images to latents
latents = vae.encode(batch["image"].to(device)).latent_dist.sample()
latents = latents * vae.config.scaling_factor
# Sample noise
noise = torch.randn_like(latents)
timesteps = torch.randint(0, noise_scheduler.num_train_timesteps, (latents.shape[0],))
timesteps = timesteps.to(device)
# Add noise
noisy_latents = noise_scheduler.add_noise(latents, noise, timesteps)
# Get text embeddings
encoder_hidden_states = text_encoder(batch["input_ids"].to(device))[0]
# Predict noise
noise_pred = unet(noisy_latents, timesteps, encoder_hidden_states).sample
# Compute loss
loss = torch.nn.functional.mse_loss(noise_pred, noise)
# Backprop
loss.backward()
optimizer.step()
lr_scheduler.step()
optimizer.zero_grad()
global_step += 1
if global_step % 100 == 0:
print(f"Step {global_step}, Loss: {loss.item():.4f}")
# Save model
pipe.unet = unet
pipe.save_pretrained(output_dir)
`
LoRA Training
Efficient fine-tuning with Low-Rank Adaptation:
`python
from peft import LoraConfig, get_peft_model
from diffusers import StableDiffusionPipeline
import torch
def train_lora(
base_model: str,
train_dataset,
output_dir: str,
lora_rank: int = 4,
learning_rate: float = 1e-4,
max_train_steps: int = 1000
):
pipe = StableDiffusionPipeline.from_pretrained(base_model)
unet = pipe.unet
# Configure LoRA
lora_config = LoraConfig(
r=lora_rank,
lora_alpha=lora_rank,
target_modules=["to_q", "to_v", "to_k", "to_out.0"],
lora_dropout=0.1
)
# Apply LoRA to UNet
unet = get_peft_model(unet, lora_config)
unet.print_trainable_parameters() # Shows ~0.1% trainable
# Train (similar to DreamBooth but only LoRA params)
optimizer = torch.optim.AdamW(
unet.parameters(),
lr=learning_rate
)
# ... training loop ...
# Save LoRA weights only
unet.save_pretrained(output_dir)
`
Textual Inversion
Learn new concepts through embeddings:
`python
from diffusers import StableDiffusionPipeline
import torch
Load with textual inversion
pipe = StableDiffusionPipeline.from_pretrained(
"stable-diffusion-v1-5/stable-diffusion-v1-5",
torch_dtype=torch.float16
).to("cuda")
Load learned embedding
pipe.load_textual_inversion(
"sd-concepts-library/cat-toy",
token="
)
Use in prompts
image = pipe("A photo of
`
Quantization
Reduce memory with quantization:
`python
from diffusers import BitsAndBytesConfig, StableDiffusionXLPipeline
import torch
8-bit quantization
quantization_config = BitsAndBytesConfig(load_in_8bit=True)
pipe = StableDiffusionXLPipeline.from_pretrained(
"stabilityai/stable-diffusion-xl-base-1.0",
quantization_config=quantization_config,
torch_dtype=torch.float16
)
`
NF4 quantization (4-bit)
`python
quantization_config = BitsAndBytesConfig(
load_in_4bit=True,
bnb_4bit_quant_type="nf4",
bnb_4bit_compute_dtype=torch.float16
)
pipe = StableDiffusionXLPipeline.from_pretrained(
"stabilityai/stable-diffusion-xl-base-1.0",
quantization_config=quantization_config
)
`
Production Deployment
FastAPI server
`python
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from diffusers import DiffusionPipeline
import torch
import base64
from io import BytesIO
app = FastAPI()
Load model at startup
pipe = DiffusionPipeline.from_pretrained(
"stable-diffusion-v1-5/stable-diffusion-v1-5",
torch_dtype=torch.float16
).to("cuda")
pipe.enable_model_cpu_offload()
class GenerationRequest(BaseModel):
prompt: str
negative_prompt: str = ""
num_inference_steps: int = 30
guidance_scale: float = 7.5
width: int = 512
height: int = 512
seed: int = None
class GenerationResponse(BaseModel):
image_base64: str
seed: int
@app.post("/generate", response_model=GenerationResponse)
async def generate(request: GenerationRequest):
try:
generator = None
seed = request.seed or torch.randint(0, 2**32, (1,)).item()
generator = torch.Generator("cuda").manual_seed(seed)
image = pipe(
prompt=request.prompt,
negative_prompt=request.negative_prompt,
num_inference_steps=request.num_inference_steps,
guidance_scale=request.guidance_scale,
width=request.width,
height=request.height,
generator=generator
).images[0]
# Convert to base64
buffer = BytesIO()
image.save(buffer, format="PNG")
image_base64 = base64.b64encode(buffer.getvalue()).decode()
return GenerationResponse(image_base64=image_base64, seed=seed)
except Exception as e:
raise HTTPException(status_code=500, detail=str(e))
@app.get("/health")
async def health():
return {"status": "healthy"}
`
Docker deployment
`dockerfile
FROM nvidia/cuda:12.1-runtime-ubuntu22.04
RUN apt-get update && apt-get install -y python3 python3-pip
WORKDIR /app
COPY requirements.txt .
RUN pip3 install -r requirements.txt
COPY . .
Pre-download model
RUN python3 -c "from diffusers import DiffusionPipeline; DiffusionPipeline.from_pretrained('stable-diffusion-v1-5/stable-diffusion-v1-5')"
EXPOSE 8000
CMD ["uvicorn", "server:app", "--host", "0.0.0.0", "--port", "8000"]
`
Kubernetes deployment
`yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: stable-diffusion
spec:
replicas: 2
selector:
matchLabels:
app: stable-diffusion
template:
metadata:
labels:
app: stable-diffusion
spec:
containers:
- name: sd
image: your-registry/stable-diffusion:latest
ports:
- containerPort: 8000
resources:
limits:
nvidia.com/gpu: 1
memory: "16Gi"
requests:
nvidia.com/gpu: 1
memory: "8Gi"
env:
- name: TRANSFORMERS_CACHE
value: "/cache/huggingface"
volumeMounts:
- name: model-cache
mountPath: /cache
volumes:
- name: model-cache
persistentVolumeClaim:
claimName: model-cache-pvc
apiVersion: v1
kind: Service
metadata:
name: stable-diffusion
spec:
selector:
app: stable-diffusion
ports:
- port: 80
targetPort: 8000
type: LoadBalancer
`
Callback System
Monitor and modify generation:
`python
from diffusers import StableDiffusionPipeline
from diffusers.callbacks import PipelineCallback
import torch
class ProgressCallback(PipelineCallback):
def __init__(self):
self.progress = []
def callback_fn(self, pipe, step_index, timestep, callback_kwargs):
self.progress.append({
"step": step_index,
"timestep": timestep.item()
})
# Optionally modify latents
latents = callback_kwargs["latents"]
return callback_kwargs
Use callback
callback = ProgressCallback()
image = pipe(
prompt="A sunset",
callback_on_step_end=callback.callback_fn,
callback_on_step_end_tensor_inputs=["latents"]
).images[0]
print(f"Generation completed in {len(callback.progress)} steps")
`
Early stopping
`python
def early_stop_callback(pipe, step_index, timestep, callback_kwargs):
# Stop after 20 steps
if step_index >= 20:
pipe._interrupt = True
return callback_kwargs
image = pipe(
prompt="A landscape",
num_inference_steps=50,
callback_on_step_end=early_stop_callback
).images[0]
`
Multi-GPU Inference
Device map auto
`python
from diffusers import StableDiffusionXLPipeline
pipe = StableDiffusionXLPipeline.from_pretrained(
"stabilityai/stable-diffusion-xl-base-1.0",
device_map="auto", # Automatically distribute across GPUs
torch_dtype=torch.float16
)
`
Manual distribution
`python
from accelerate import infer_auto_device_map, dispatch_model
Create device map
device_map = infer_auto_device_map(
pipe.unet,
max_memory={0: "10GiB", 1: "10GiB"}
)
Dispatch model
pipe.unet = dispatch_model(pipe.unet, device_map=device_map)
`